1. Field of Invention
This invention is directed to an integrated dipole detector for microwave imaging systems.
2. Description of Related Art
In conventional microwave imaging systems, various halfwave antennas have been used to receive energy from a transmitted antenna to image an object in the field of the receiving antennas. It is well known that a very simple and effective halfwave receiving antenna can be formed by connecting quarter wavelength conducting arms to the end of the inner and outer conductors of an exposed coaxial cable to form a halfwave dipole antenna. Time-harmonic electromagnetic voltages that are induced on the halfwave dipole antenna are detected by a microwave-frequency sensitive rectifier, such as, for example, a diode located at a base of the coaxial cable.
It is well appreciated that the fabrication of conventional coaxial-dipole receiving antennas are not readily amenable to methods suited for mass production. That is, conventional coaxial-dipole receiving antennas are typically manufactured xe2x80x9cby handxe2x80x9d. Therefore, conventional coaxial-dipole receiving antennas are often very dependent on the relative skill of the craftsman. Thus, conventional coaxial-dipole receiving antennas suffer from lack of uniformity and quality, and are often unwieldy in size and expensive.
There is a need in the microwave imaging community for a compact and easily replicatable dipole receiving antenna.
This invention provides various exemplary embodiments of a compact dipole receiving antenna with an integrated detector. In particular, photolithographic and/or printed circuit board printing techniques can be used to fabricate a microwave-frequency dipole antenna with an integrated Schottky diode located between the opposing arms of a halfwave dipole radiator.
In various exemplary embodiments, the rectified field voltages may be filtered or further detected by placing capacitors and/or resistors in series or in parallel to the integrated Schottky diode. Because photolithographic and/or printed circuit board printing techniques can be used to fabricate the dipole antenna, the quality and compactness of the dipole detector can be greatly increased.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the exemplary embodiments.